fuser
Ever tried to unmount a drive only to get hit with a mysterious “in use” message?
Even when you are sure you are not using it?
Yea, that was one of the early problems that made learning linux tough. Then I learned about the fuser command:
fuser -v /path/to/mount
You will get back what process is still using that mountpoint, and who owns that process:
USER PID ACCESS COMMAND
root 2117 ..C… /bin/bash
As you can see, I accidentally left a terminal open. Oops.
Related Links
- fuser at linuxcommand.org
- Also this linuxjournal article.


